Highly cytotoxic platinum (II)/(IV) coordination complexes, like cisplatin and its derivatives (carboplatin/oxaliplatin), are well-known potent anticancer agents. Pharmacologically inactive forms of these compounds, otherwise known as prodrugs, have been developed to optimize the drug delivery process, e.g. tumor selectivity, water solubility and cell permeability, before subsequent activation at the target sites. Despite the clinical success of several prodrugs, it remains an unprecedented challenge to achieve the desired pharmacokinetics, with minimal adverse side effects, since they are non-specifically distributed throughout the body. The major drawback of prodrugs, according to the literature, is linked to difficulties in tracing their activities in-vitro or in-vivo. Intriguingly, the recent advent of theranostic nanomedicine, an emerging paradigm of combining diagnostic and therapeutic entities into one, creates a new research landscape and provides a promising solution to the prodrug conundrum.
Theranostic technology affords simultaneous imaging diagnosis and targeted therapy of diseases. Theranostic nanoagents of diagnostic capability and therapeutic efficacy can be, for instance, used in pathological mechanistic studies and can guide pre-/post-treatment assessment due to their responsive signaling capability, e.g. magnetic resonance and fluorescence in-vitro or in-vivo studies. Biodistribution information can be obtained and photocontrolled drug release/photodynamic therapy manipulated. Borrowing the concept from the nano-counterparts, it is an objective of the present disclosure to provide additional theranostic molecular prodrugs with improved therapeutic and/or diagnostic properties.